Android的对话框常用的有两种：PopupWindow和AlertDialog。PopupWindow顾名思义为弹出菜单，不同于AlertDialog对话框，PopupWindow弹出的位置可以很多变化，按照有无偏移分，可以分为无偏移和偏移两种；按照参照类型不同又可以分为两种：相对某个控件（Anchor锚）的位置和父容器内部的相对位置。具体如下：函数 简介 showAsDropDown(View anchor) 相对某个控件的位置（正左下方），无偏移 showAsDropDown(View anchor, int xoff, int yoff) 相对某个控件的位置，有偏移（正数表示下方右边，负数表示（上方左边）） showAtLocation(View parent, int gravity, int x, int y) 父容器容器相对位置，例如正中央Gravity.CENTER，下方Gravity.BOTTOM等下面是运行程序截图： 下面是运行程序截图：                     程序代码：布局：main.xml
        
        
                 
               
                    
               
                          
     
        
        
                
                
            
                
             
         
             代码：       package com.myAndroid.test;       import Android.app.Activity;    import Android.content.Context;    import Android.content.SharedPreferences.Editor;    import Android.os.Bundle;    import Android.util.Log;    import Android.view.Gravity;    import Android.view.LayoutInflater;    import Android.view.View;    import Android.view.View.OnClickListener;    import Android.view.ViewGroup.LayoutParams;    import Android.widget.Button;    import Android.widget.EditText;    import Android.widget.Gallery;    import Android.widget.PopupWindow;    import Android.widget.TextView;       public class PopupWindowTest extends Activity {
   //PopupWindow属于不阻塞的对话框，AlertDialog则是阻塞的。        private Button bt_popupWindow1;        private Button bt_popupWindow2;        private Button bt_popupWindow3;        private Button bt_popupWindow4;        private TextView tv_showText;        private PopupWindow popupWindow;        private int screenWidth;        private int screenHeight;        private int dialgoWidth;        private int dialgoheight;                   /** Called when the activity is first created. */       @Override       public void onCreate(Bundle savedInstanceState) {            super.onCreate(savedInstanceState);            setContentView(R.layout.main);                        initView();        }                /**        * 初始化控件和响应事件        */       private void initView() {            bt_popupWindow1 = (Button)findViewById(R.id.bt_PopupWindow1);            bt_popupWindow2 = (Button)findViewById(R.id.bt_PopupWindow2);            bt_popupWindow3 = (Button)findViewById(R.id.bt_PopupWindow3);            bt_popupWindow4 = (Button)findViewById(R.id.bt_PopupWindow4);            tv_showText = (TextView)findViewById(R.id.tv_showText);                        bt_popupWindow1.setOnClickListener(new ClickEvent());            bt_popupWindow2.setOnClickListener(new ClickEvent());            bt_popupWindow3.setOnClickListener(new ClickEvent());            bt_popupWindow4.setOnClickListener(new ClickEvent());                                            }                /**        * 按钮点击事件处理        * @author Kobi        *        */       private class ClickEvent implements OnClickListener {                        @Override           public void onClick(View v) {                // TODO Auto-generated method stub                switch(v.getId()) {                                    case R.id.bt_PopupWindow1:  //以自己为Anchor，不偏移                    getPopupWindow();                    popupWindow.showAsDropDown(v);                    break;                                    case R.id.bt_PopupWindow2:  //以自己为Anchor，偏移(screenWidth-dialgoWidth)/2, 0)--按钮正下方                    getPopupWindow();                    popupWindow.showAsDropDown(v, (screenWidth-dialgoWidth)/2, 0);                    break;                                    case R.id.bt_PopupWindow3:  //以屏幕中心为参照，不偏移                    getPopupWindow();                    popupWindow.showAtLocation(findViewById(R.id.layout), Gravity.CENTER, 0, 0);                    break;                                    case R.id.bt_PopupWindow4:  //以屏幕左下角为参照，偏移(screenWidth-dialgoWidth)/2, 0) --屏幕下方中央                    getPopupWindow();                    popupWindow.showAtLocation(findViewById(R.id.layout),                             Gravity.BOTTOM, 0, 0);                    break;                                    default:                    break;                }            }                    }           /**        * 创建PopupWindow        */       protected void initPopuptWindow() {            // TODO Auto-generated method stub                                    View popupWindow_view = getLayoutInflater().inflate(    //获取自定义布局文件dialog.xml的视图                    R.layout.dialog, null,false);                        popupWindow = new PopupWindow(popupWindow_view, 200, 150, true);//创建PopupWindow实例                        Button bt_ok = (Button)popupWindow_view.findViewById(R.id.bt_ok);   //dialog.xml视图里面的控件            Button bt_cancle = (Button)popupWindow_view.findViewById(R.id.bt_cancle);            final EditText et_text = (EditText)popupWindow_view.findViewById(R.id.et_text);                         bt_ok.setOnClickListener(new OnClickListener() {                                @Override               public void onClick(View v) {                    // TODO Auto-generated method stub                    tv_showText.setText(et_text.getText()); //在标签里显示内容                    popupWindow.dismiss();                  //对话框消失                }            });                        bt_cancle.setOnClickListener(new OnClickListener() {                                @Override               public void onClick(View v) {                    // TODO Auto-generated method stub                    popupWindow.dismiss();                }            });                        //获取屏幕和对话框各自高宽            screenWidth = PopupWindowTest.this.getWindowManager().getDefaultDisplay().getWidth();            screenHeight = PopupWindowTest.this.getWindowManager().getDefaultDisplay().getHeight();               dialgoWidth = popupWindow.getWidth();            dialgoheight = popupWindow.getHeight();                    }                /*        * 获取PopupWindow实例        */       private void getPopupWindow() {                        if(null != popupWindow) {                popupWindow.dismiss();                return;            }else {                initPopuptWindow();            }        }           @Override       protected void onPause() {            // TODO Auto-generated method stub            super.onPause();            Log.e("ActivityState", "onPause");        }           @Override       protected void onResume() {            // TODO Auto-generated method stub            super.onResume();            Log.e("ActivityState", "onResume");        }                               }